Begin internal reorganization.

This begins reorganizing how translation and compilation occur, and
setting up infrastructure for imports/exports and relocations. It
splits parts out of StandaloneRuntime, forming Module, Compilation,
and Instance structs, which can be used more independently.

It also simplifies the command-line interface, in a step towards
making simple tools that just expose the functionality of the
libraries.

lib/obj/src/emit_module.rs

@@ -1,59 +1,18 @@
-use cretonne::Context;
 use cretonne::settings;
-use cretonne::isa::TargetIsa;
-use cretonne::verify_function;
-use cretonne::verifier;
 use cretonne::settings::Configurable;
-use cretonne::result::CtonError;
-use cretonne::ir::entities::AnyEntity;
-use cretonne::ir::{self, Ebb, FuncRef, JumpTable, Function};
-use cretonne::binemit::{RelocSink, Reloc, CodeOffset};
-use cton_wasm::TranslationResult;
-use std::fmt::Write;
 use faerie::Artifact;
 use wasmstandalone_runtime;
 
-type RelocRef = u16;
-
-// Implementation of a relocation sink that just saves all the information for later
-struct FaerieRelocSink {
-    ebbs: Vec<(RelocRef, Ebb, CodeOffset)>,
-    funcs: Vec<(RelocRef, FuncRef, CodeOffset)>,
-    jts: Vec<(RelocRef, JumpTable, CodeOffset)>,
-}
-
-impl RelocSink for FaerieRelocSink {
-    fn reloc_ebb(&mut self, offset: CodeOffset, reloc: Reloc, ebb: Ebb) {
-        self.ebbs.push((reloc.0, ebb, offset));
-    }
-    fn reloc_func(&mut self, offset: CodeOffset, reloc: Reloc, func: FuncRef) {
-        self.funcs.push((reloc.0, func, offset));
-    }
-    fn reloc_jt(&mut self, offset: CodeOffset, reloc: Reloc, jt: JumpTable) {
-        self.jts.push((reloc.0, jt, offset));
-    }
-}
-
-impl FaerieRelocSink {
-    fn new() -> FaerieRelocSink {
-        FaerieRelocSink {
-            ebbs: Vec::new(),
-            funcs: Vec::new(),
-            jts: Vec::new(),
-        }
-    }
-}
-
 /// Emits a module that has been emitted with the `WasmRuntime` runtime
 /// implementation to a native object file.
-pub fn emit_module(
-    trans_result: &TranslationResult,
+pub fn emit_module<'module>(
     obj: &mut Artifact,
-    isa: &TargetIsa,
-    runtime: &wasmstandalone_runtime::Runtime,
+    compilation: &wasmstandalone_runtime::Compilation<'module>,
+    relocations: &wasmstandalone_runtime::Relocations,
 ) -> Result<(), String> {
     debug_assert!(
-        runtime.start_func.is_none() || runtime.start_func.unwrap() >= runtime.imported_funcs.len(),
+        compilation.module.start_func.is_none() ||
+            compilation.module.start_func.unwrap() >= compilation.module.imported_funcs.len(),
         "imported start functions not supported yet"
     );
 
@@ -62,55 +21,15 @@ pub fn emit_module(
         "Missing enable_verifier setting",
     );
 
-    for function in &trans_result.functions {
-        let mut context = Context::new();
-        verify_function(function, isa).unwrap();
-        context.func = function.clone(); // TODO: Avoid this clone.
-        let code_size = context.compile(&*isa).map_err(|e| {
-            pretty_error(&context.func, Some(isa), e)
-        })? as usize;
-        if code_size == 0 {
-            return Err(String::from("no code generated by Cretonne"));
-        }
-        let mut code_buf: Vec<u8> = Vec::with_capacity(code_size);
-        code_buf.resize(code_size, 0);
-        let mut relocsink = FaerieRelocSink::new();
-        context.emit_to_memory(code_buf.as_mut_ptr(), &mut relocsink, &*isa);
+    for (i, function_relocs) in relocations.iter().enumerate() {
+        assert!(function_relocs.is_empty(), "relocations not supported yet");
+        let body = &compilation.functions[i];
 
-        // FIXME: get the real linkage name of the function
-        obj.add_code("the_function_name", code_buf);
-
-        assert!(relocsink.jts.is_empty(), "jump tables not yet implemented");
-        assert!(relocsink.ebbs.is_empty(), "ebb relocs not yet implemented");
-        assert!(
-            relocsink.funcs.is_empty(),
-            "function relocs not yet implemented"
+        obj.add_code(
+            wasmstandalone_runtime::get_func_name(compilation.module.imported_funcs.len() + i),
+            body.clone(),
         );
-
-        // FIXME: handle imports
     }
 
     Ok(())
 }
-
-/// Pretty-print a verifier error.
-fn pretty_verifier_error(func: &Function, isa: Option<&TargetIsa>, err: verifier::Error) -> String {
-    let mut msg = err.to_string();
-    match err.location {
-        AnyEntity::Inst(inst) => {
-            write!(msg, "\n{}: {}\n\n", inst, func.dfg.display_inst(inst, isa)).unwrap()
-        }
-        _ => msg.push('\n'),
-    }
-    write!(msg, "{}", func.display(isa)).unwrap();
-    msg
-}
-
-/// Pretty-print a Cretonne error.
-fn pretty_error(func: &ir::Function, isa: Option<&TargetIsa>, err: CtonError) -> String {
-    if let CtonError::Verifier(e) = err {
-        pretty_verifier_error(func, isa, e)
-    } else {
-        err.to_string()
-    }
-}